The purpose of this project is to study radiation sensitizing compounds and their ability to increase the effect of radiation in sterilizing neoplastic cells. The plan is to include patients who have carcinoma of the esophagus that appears to be clinically confined to the mediastinum and administer preoperative irradiation to all patients. Half of the patients will receive misonidazole, a hypoxic cell sensitizer, intravenously. Following completion of the radiotherapy, surgery will be performed and survival, freedom from lapse, and tumor viability within the pathologic specimen will all be evaluated. In addition, these patients, who are frequently cachetic, will serve as the basis for controlled studies of total parenteral nutrition.